Two senior Australian government ministers on Monday brushed off reports that they might challenge Prime Minister Tony Abbott's leadership as an opinion poll showed a further fall in his popularity.

Speculation is growing that the ruling Liberal Party will replace Abbott, who led his conservative coalition to victory at elections in September 2013, but who has recently been declining in popularity.

Fairfax Media reported on Monday that Communications Minister Malcolm Turnbull, the party's former leader, and Foreign Minister Julie Bishop are under pressure from colleagues to challenge Abbott for the leadership in a ballot of Liberal lawmakers.

Bishop said she supported Abbott. Turnbull did not directly answer when asked at a press conference whether he was interested in regaining the party leadership he lost to Abbott by a single vote in 2009.

"The only thing we should be interested in on the political front today is the prime minister's speech to the National Press Club," Turnbull said, referring to an address scheduled for later Thursday.

Abbott will use the speech to present his agenda for 2015 as an attempt to turn around his government's poor standing in opinion polls.

Pressure has been building on Abbott's leadership since he angered many within government ranks last week by making the husband of Queen Elizabeth II, Prince Philip, an Australian knight. The announcement on Australia's national day was seen as an insult to deserving Australian citizens.

Abbott has apologized for his lack of consultation with cabinet colleagues for that decision, which has been blamed in part for a surprise loss by the conservative government in elections on Saturday in Queensland state.

A poll by market researcher Ipsos published by Fairfax Media newspaper Monday showed that the opposition Labor Party was clearly more popular than Abbott's government. It found 54 percent of respondents referred Labor and 46 percent preferred the government — a reversal of the 2013 election result that delivered the government a clear majority.

Abbott's approval rating had declined from 38 percent in December to 29 percent in the latest poll.

Opposition leader Bill Shorten's approval rating had climbed in the same period from 46 percent to 48 percent, although that change was within the poll's 2.6 percent margin of error.

The poll was based on a random nationwide telephone survey of 1,405 voters from Thursday through Saturday of last week.